root / scout_avr / src / Atmega128rfa1.cpp @ 88fb3a79
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1 | 88fb3a79 | Tom Mullins | #include "Atmega128rfa1.h" |
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2 | |||
3 | extern "C" |
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4 | { |
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5 | #include <avr/io.h> |
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6 | #include <avr/interrupt.h> |
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7 | } |
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8 | |||
9 | unsigned long millis; |
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10 | |||
11 | Atmega128rfa1::Atmega128rfa1() |
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12 | { |
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13 | } |
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14 | |||
15 | ISR(TIMER0_COMPA_vect) |
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16 | { |
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17 | millis++; |
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18 | } |
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19 | |||
20 | void Atmega128rfa1::init()
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21 | { |
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22 | // === init serial ===
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23 | // for 16 MHz clock, 76800 baud
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24 | uint16_t baud = 12;
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25 | UBRR0H = baud >> 8;
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26 | UBRR0L = baud; |
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27 | // UMSEL0 = 0, asynchronous usart
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28 | // UPM0 = 0, parity check disabled
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29 | // USBS0 = 0, 1 stop bit
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30 | // UCSZ0 = 3, 8-bit
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31 | UCSR0B = _BV(RXEN0) | _BV(TXEN0); |
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32 | UCSR0C = _BV(UCSZ01) | _BV(UCSZ00); |
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33 | |||
34 | // === init time ===
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35 | // COM0x = 0, pin OC0x not used
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36 | // WGM0 = 2, clear timer on compare match, TOP = OCRA
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37 | // CS0 = 3, 64 prescaler
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38 | TCCR0A = _BV(WGM01); |
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39 | TCCR0B = _BV(CS01) | _BV(CS00); |
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40 | // enable interrupt on compare match A
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41 | TIMSK0 = _BV(OCIE0A); |
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42 | // (1 ms) * 16 MHz / 64 prescaler = 250
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43 | OCR0A = 250;
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44 | millis = 0;
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45 | } |
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46 | |||
47 | int Atmega128rfa1::read()
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48 | { |
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49 | // TODO make a rx buffer
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50 | if (UCSR0A & _BV(RXC0)) return UDR0; |
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51 | else return -1; |
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52 | } |
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53 | |||
54 | void Atmega128rfa1::write(uint8_t* data, int length) |
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55 | { |
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56 | // TODO make this non-blocking with a tx buffer
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57 | int i;
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58 | for (i = 0; i < length; i++) |
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59 | { |
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60 | while (!(UCSR0A & _BV(UDRE0)));
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61 | UDR0 = data[i]; |
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62 | } |
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63 | } |
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64 | |||
65 | unsigned long Atmega128rfa1::time() |
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66 | { |
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67 | unsigned long ret; |
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68 | cli(); |
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69 | ret = millis; |
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70 | sei(); |
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71 | return ret;
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72 | } |